The alkali-developable, colored photosensitive resin composition is an alkali-developable resin composition containing a specific compound having an ethylenically unsaturated bond, a colorant including a pigment and a dye, and a photopolymerization initiator. Capable of curing by polymerization on being irradiated with ultraviolet light or an electron beam, the alkali-developable photosensitive resin composition is applicable to photo-curing inks, photosensitive printing plates, printed wiring boards, various kinds of photoresists, color filters, and so forth.
The recent developments in downsizing and function enhancement of electronic equipment have boosted the demand for fine and precise patterning technology by lithography. In particular, an alkali-developable, colored photosensitive resin composition for color filter application has been required to have higher color purity and higher light shielding performance. Among approaches to meet the demand is a technique of dispersing a pigment or a dye in high concentration in an alkali-developable photosensitive resin. This technique involves a problem that an increase in the proportion of a pigment or a dye in the alkali-developable, colored photosensitive resin composition results in blocking ultraviolet light necessary for patterning and thereby resulting in reduction of sensitivity. A reduction in sensitivity necessitates extension of an exposure time, which can result in reduction of productivity. Therefore, an alkali-developable, colored photosensitive resin composition is required to have sufficient sensitivity, resolving power, intimate adhesion, and alkali resistance.
Alkali developable, colored photosensitive resin compositions heretofore proposed include a photosensitive composition having a coloring component, a polyfunctional thiol compound, and a photo initiator dispersed in a binder containing an acrylic copolymer having a carboxyl group and an ethylenically unsaturated group in the side chain thereof (see, for example, Patent Document 1). Containing a polyfunctional thiol component as an essential component, the composition has associated problems of smell and storage stability. Patent Document 2 discloses a colored photosensitive resin composition comprising an unsaturated group-containing resin and a photopolymerization initiator selected from a triazine compound, an acetophenone compound, and a biimidazole compound. Patent Document 3 and Patent Document 4 disclose an alkali-soluble unsaturated resin and a radiation sensitive resin composition containing the resin. These known alkali-developable photosensitive resin compositions have insufficient sensitivity for forming a proper pattern or a fine pattern and are therefore unsatisfactory for producing high quality color filters.
Patent Document 1: JP-A-5-281734
Patent Documennt 2: JP-A-2004-138950
Patent Document 3: Japanese Patent 3148429
Patent Document 4: JP-A-2003-89716: